What format (WMF, JPG, PNG) were the images in the original ODT? Conversion to DOCX will also convert image formats for some types and if no effective image filter is available this can cause problems.
The answer is simple: Microsoft Office does not fully support the office document standard ODF.
However our developers give their best to create filters to Microsoft’s often changing formats.
As you use version 188.8.131.52 I recommend to upgrade to 184.108.40.206 or 4.3.1. These versions have improvements also in respect to the Microsoft office filters.